Hi serializers, archivers, boosters and Robert, I've used boost:serialization (boost 1.34.1 under Linux ubuntu and/or SL4,, gcc 4.2) for one year. Thanks to this excellent library, our team store critical experimental data (3 TB using zipped text archives). Up to now, I met no problem with text/XML archives as all the stored double values pass the 'isnormal' check. Now my new data analysis programs needs to (de)serialize doubles even if they are NaNs or infinites (for it makes sense for me). Unfortunately, the load method for double fails while reading 'nan' (or 'inf') from the input for this is the standard behavior of the ostream with "! isnormal" doubles. After studying the source code for boost text oriented I/O archives in the hope to find a fix for my problem, I made an attempt to make boost aware of nans and +/-infs in a pragmatic way (I mean trying to save time and storage but keep the information and get rid of the stream error exception). I attached a tiny tarball to show the hack I've done. I'm not sure at all this is be a definitively good and elegant approach to handle nans within text based archives. So I'd appreciate to get some feedback and comments from Robert or any expert in this field. As I work only with Linux, gcc and 1.34.1, this approach is likely not to be portable... but maybe this could initiate some work to fix it in an official way. thanks for your attention and for all this very very useful material. regards frc -- Francois Mauger Laboratoire de Physique Corpusculaire de Caen et Universite de Caen ENSICAEN - 6, Boulevard du Marechal Juin, 14050 CAEN Cedex, FRANCE e-mail: mauger@lpccaen.in2p3.fr tel.: (0/+33) 2 31 45 25 12 fax: (0/+33) 2 31 45 25 49